The invention relates, in general, to a punch device and, in particular, to a punch device intended for punching holes into “green sheets” (unfired ceramic substrates).
When punching green sheets, a large number of holes are to be made in a ceramic substrate. To achieve this, an appropriate number of punches are used. The punches are aligned parallel to each other and are simultaneously pushed through the green sheet. In so doing, the green sheet is situated on a die having corresponding punch openings.
Such a punch device has been known, for example, from DE 198 55 578 A1 and U.S. Pat. No. 6,481,323 B1. The punch device comprises a lower and an upper tool part, whereby the lower tool part is a die. The upper tool part comprises a guide plate with punch guides in which the shafts of the punches can be moved back and forth in vertical direction. Each punch has a head that is connected to a drive device via a coupling. The drive device comprises one or more drives that move the coupling device linearly up and down in order to move the punches.
If such punches are to be replaced, the drive device needs to be removed. To do so, the drive unit is shifted laterally, whereby the fork-shaped coupling devices expose the heads of the punches. The punches are removed from the carrier plate in order to hold them in an upper position.
The fork-shaped couplings and the shifting mechanism for moving the drive carrier plate and the punches must be fabricated with extreme precision. The manufacture and tolerance adaptation are complex and cost-intensive. Tolerance fluctuations and an improper shifting of the coupling parts can result in damage to, or the destruction of, the stamps.
Considering this, it is the object of the invention to provide a punch device which is easier to manufacture and handle and is more robust.